A small dose of widely used tranquilizer allows people to lie during lie detector tests without being discovered. The stress responses that lie detector tests measure can be inhibited by the drug without noticeable side effects. One of the implications of this fact is that the drug can also be

effective in reducing stress in everyday situations.

An assumption of the passage is that

Tranquilizers are always an effective treatment for stress

The inhibition of stress responses increases subjective stress

Stress as measured by a lie detector is similar to everyday stress

Persons who lie during a lie detector test always display signs of stress